Device for cleaning tubes through which a current of dust-containing gas flows



My 1970 DEYNAT 3,520,015

a DEVICE FOR CLEANING TUBES THROUGH WHICH A CURRENT OF DUST*CONTAINING GAS FLOWS mm Aug. 6. 1968 United States Patent 3 520 015 DEVICE FOR CLEANIP IG TUBES THROUGH WHICH A CURRENT OF DUST-CONTAIN- ING GAS FLOWS .Grard Deynat, Chalon-sur-Saone, France, assignor to Int. Cl. lsosb 9/02 US. Cl. 15104.1 2 Claims ABSTRACT OF THE DISCLOSURE The invention provides a device for cleaning a gas flow tube, the device comprising a rotatable chain in the tube and driving means therefor.

The invention relates to a device for cleaning tubes through which a current of dust-containing gas flows, more particularly for cleaning the tubes for sampling dustcontaining gases in the smoke circuits of kilns. The continuous analysis of the gas leaving kilns requires the use of a sample representing the composition of the gases. A considerable amount of dust and volatile products which are liable to condense often clogs the tubes, so that they must be cleaned while the analysing installation is stopped, the result being errors in the measurements.

To enable an automatic installation to operate in a stable manner for determining the composition of gases using samples of the gases as the regulating and checking element, the sampling of the gases must be performed for |very long periods without interruption. To this end, the invention relates to a device enabling the sampling tubes to be continuously cleaned.

According to the invention, the tube is inclined to the vertical, and the cleaning device comprises a chain with links extending inside the tube over at least a portion of its length, a member for rotating the chain around its longitudinal axis, and a system for displacing the chainentraining member over a certain length of its axis.

An exemplary embodiment of the description will now be described with reference to the accompanying drawings, wherein:

FIG. 1 is a diagrammatic sectional view of a sampling tube including the device according to the invention;

FIG. 2 is a perspective view of the system for the longitudinal displacement of the chain-entraining member.

According to the invention a sampling tube 1 entering an enclosure 2 containing the gas to be analysed is disposed at a certain angle with the vertical. The tube 1 is closed at the top by a hood 3 and discharges into a branch conduit 4 which directs the gases to the measuring apparatuses.

A chain having oblong links 5 extends inside the tube through its entire length. The chain 5 is suspended from a rod 6 which extends through the upper hood 3, and is rotated by a control group 7 through a coupling 8. In the embodiment illustrated in the drawings, the coupling allows the rod to make a displacement of limited amplitude along its axis during rotation. The rod 6 is supported by a roller 9 rotatably mounted on a shaft 10 attached to the rod and rolling over a track 11 centered on the axis of the rod during the rotation thereof.

Since the tube is inclined, the chain links bear against the inner wall of the tube, substantially along a generatrix. Thus, when the rod 6 rotates, the rotation is transmitted successively to the links, which tilt abruptly one after the other. These abrupt movements of the links transmitted to the tube wall cause the dust entrained by the gases in the tube and deposited on the chain and on the tube walls to fall downwardly in the tube.

The links are so designed that during chain rotation each link remains free to pivot through a certain angle in relation to the adjacent links, thus assuring the abrupt rotation of the chain. However, the chain may have a tendency to become twisted, and must be shaken periodically. To this end, the track 11 over which the chain-supporting roller 9 rolls, takes the form of a cam composed of an ascending helical ramp 12 whose ends are connected by a ramp 13 parallel with the longitudinal axis.

Thus, during chain rotation, the roller 9 rolling on the ramp 12 progressively causes the chain to move upwards, and then roller 9 suddenly drops along the ramp 13, thus causing a sudden drop of the chain in the tube; the resulting shock facilitates the descent of the dust, and untwists the chain.

The assembly of the group controlling the rod 6 and the hood 3 is mounted on a support 14 which can be tilted to free the tube opening, thus allowing quick manual cleaning of the tube or replacing the chain.

The device described hereinbefore therefore allows the continuous cleaning of the sampling tube, whatever its length may be. The device may operate at elevated temperatures in the tube and can be deformed without impairing the cleaning.

Of course, the invention is not limited to the details of the embodiment described hereinbefore, and such details can be modified without exceeding the scope of the invention. For instance, the chain can be shorter than the tube, its length and the size of its links being selected 111 relation to the liability to dust-clogging. The length of the tube does not matter, it depends on the characteristics or the installation, and it can be very long.

The control group is shown disposed on a support attached to the tube, but the control group could be located in some other place and drive the control rod through a belt.

Lastly, the device is particularly applicable to installations for producing cement by the wet or dry methods, but the device could be used for other industries than the cement industry, in all cases in which a current of porton of its length, means for rotating the chain around its longitudinal axis, means for reciprocating the chain, a rod from which the chain is suspended, said means for rotating the chain rotating the rod, a control group and a suspension member for said rod, the suspension m mber including a roller rotatably mounted on a support attached to the rod and rolling during rotation of the rod over a track centered about the axis of the tube.

2. A cleaning device as set forth in claim 1, said track comprising a helical cam the ends of said cam being connected by a ramp substantially parallel to the tube axis.

References Cited UNITED STATES PATENTS 1,898,596 2/1933 Piatt 165-95 X 2,454,884 11/1948 Peaden 15-'242 X 21,641,791 6/1953 Wells 15163 X FOREIGN PATENTS 7,777 8/1838 Great Britain. 12,012 6/1899 Great Britain.

ROBERT W. MICHELL, Primary Examiner 

